Monolayer and Multilayer Particle Deposits on Hard Surfaces: Literature Review and Implications for Particle Resuspension in the Indoor Environment

Abstract

Particle deposits on indoor surfaces can be as complex and diverse as the indoor environments in which they exist. Dust loading can range over several orders of magnitude, suggesting the existence of different types of particle deposits. These deposits can be broadly classified as either a monolayer, in which particles are sparsely deposited on a surface, or a multilayer, in which particles are deposited on top of one another and there is particle-toparticle adhesion and interaction. Particles within these diverse structures of settled indoor dust can become airborne through a process known as resuspension, which can occur due to airflow in ventilation ducts or human activity indoors. The dust loading and deposit structure on an indoor surface may have important implications for resuspension in the indoor environment. This literature review provides a summary of dust loads found on indoor surfaces in field studies and classifies each dust load as either a monolayer or multilayer particle deposit. The article highlights the unique attributes associated with resuspension from both types of particle deposits by summarizing key findings of the experimental resuspension literature. The fundamental differences in the resuspension process between monolayer and multilayer deposits suggest that resuspension may vary considerably among the broad spectrum of dust loads found on indoor surfaces.

Monte Carlo modelling of particle resuspension on a flat surface

“…Besides, in practice, many problems of particle resuspension involve the presence of multilayer deposits, which add greater complexity related to mutual obstruction of particles, the formation and eventual resuspension of clusters and the dependence of the resuspension process on the structure of the deposit (Ziskind, 2006;Gradón, 2009;Boor et al, 2013;Henry & Minier, 2014b;Hanus et al, 2007). Many models have been developed in the last two decades.…”

Particle deposition and resuspension in gas-cooled reactors—Activity overview of the two European research projects THINS and ARCHER

“…No. of Pages 8 T. Barth et al / Nuclear Engineering and Design xxx (2015) xxx-xxx Recently, Wang et al (2012) and Boor et al (2013) performed wind tunnel experiments on multilayer resuspension and their results also indicated the beginning of multilayer particle resuspension at lower fluid velocities than single particle resuspension.…”

“…Reasons for the deviations are probably found in the simplified model assumptions of the numerical simulations and the incomplete determination of the experimental boundary conditions. For further literature on particle resuspension the reader may be referred to state-of-the art reviews of Ziskind et al (1995), Ziskind (2006) and of Boor et al (2013). Barth et al (2014c) performed a series of monolayer particle resuspension experiments in a horizontal square duct under controlled boundary conditions to minimize the uncertainties of previous investigations and to provide a high-quality data set for the development of numerical models.…”

Experimental investigation of jet-induced resuspension of indoor deposited particles

“…The surface dust load in indoor environments ranges across several orders of magnitudes. For example, the dust load on hard flooring is typically in the range of 0.1 to 1 g/m 2 but in ventilation ducts it may vary from less than 1 g/m 2 to over 100 g/m 2 (Boor et al 2013). Figure 2 shows pictures of deposited dusts on the rough stainless steel plates at different surface dust loads.…”